336 



AUGUSTO BONAZZI 



seen later these same structures are utilized in future life and 

 should therefore be considered again in the calculation of n,that 

 quantity of sugar which goes to the maintenance of the cell.^ 

 The above analysis of the literature leads us to the following 

 considerations: a) the C:N ratio of Azotobacter is an inconstant 

 value, b) the metabolism of this organism is not as yet well 

 understood, c) the nitrogen fixing capacity of this organism 

 seems to be a function of secondary importance in the cell 

 economy. 



II. EXPEKIMENTAL 



Carbon relations 



C02:02 ratio and sugar consumption 



Experiment 44- A. large flat-bottomed Fernbach flask was 

 fitted with the attachment shown in figure 1. 



Fig. 1. a, culture flask; b, d, e, gas collecting chain; c, mercury valve;/, culture 

 solution; x, paraffin and plaster of paris seal fitted over the ground glass stoppers 

 to avoid possible gas leaks. 



The total volume of the apparatus was 3290 cc. and since 

 100 cc. of solution were used, the total volume of air over the 

 solution was 3190 cc. The solution used was of the following 

 composition : 



Deep well water 500. 00 cc. 



K2HPO4 0. 10 gram 



Glucose 10.00 grams 



2 Krainsky obtains curves on the CO2 production of cultures of Azotobacter 

 but unfortunately gives no data on the actual sugar consumption. 



